001 /*
002 * Copyright 1994-2001 Sun Microsystems, Inc. All Rights Reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation. Sun designates this
008 * particular file as subject to the "Classpath" exception as provided
009 * by Sun in the LICENSE file that accompanied this code.
010 *
011 * This code is distributed in the hope that it will be useful, but WITHOUT
012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014 * version 2 for more details (a copy is included in the LICENSE file that
015 * accompanied this code).
016 *
017 * You should have received a copy of the GNU General Public License version
018 * 2 along with this work; if not, write to the Free Software Foundation,
019 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020 *
021 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022 * CA 95054 USA or visit www.sun.com if you need additional information or
023 * have any questions.
024 */
025
026 package java.lang;
027
028 /**
029 * The abstract class <code>Number</code> is the superclass of classes
030 * <code>BigDecimal</code>, <code>BigInteger</code>,
031 * <code>Byte</code>, <code>Double</code>, <code>Float</code>,
032 * <code>Integer</code>, <code>Long</code>, and <code>Short</code>.
033 * <p>
034 * Subclasses of <code>Number</code> must provide methods to convert
035 * the represented numeric value to <code>byte</code>, <code>double</code>,
036 * <code>float</code>, <code>int</code>, <code>long</code>, and
037 * <code>short</code>.
038 *
039 * @author Lee Boynton
040 * @author Arthur van Hoff
041 * @version 1.36, 05/05/07
042 * @see java.lang.Byte
043 * @see java.lang.Double
044 * @see java.lang.Float
045 * @see java.lang.Integer
046 * @see java.lang.Long
047 * @see java.lang.Short
048 * @since JDK1.0
049 */
050 public abstract class Number implements java.io.Serializable {
051 /**
052 * Returns the value of the specified number as an <code>int</code>.
053 * This may involve rounding or truncation.
054 *
055 * @return the numeric value represented by this object after conversion
056 * to type <code>int</code>.
057 */
058 public abstract int intValue();
059
060 /**
061 * Returns the value of the specified number as a <code>long</code>.
062 * This may involve rounding or truncation.
063 *
064 * @return the numeric value represented by this object after conversion
065 * to type <code>long</code>.
066 */
067 public abstract long longValue();
068
069 /**
070 * Returns the value of the specified number as a <code>float</code>.
071 * This may involve rounding.
072 *
073 * @return the numeric value represented by this object after conversion
074 * to type <code>float</code>.
075 */
076 public abstract float floatValue();
077
078 /**
079 * Returns the value of the specified number as a <code>double</code>.
080 * This may involve rounding.
081 *
082 * @return the numeric value represented by this object after conversion
083 * to type <code>double</code>.
084 */
085 public abstract double doubleValue();
086
087 /**
088 * Returns the value of the specified number as a <code>byte</code>.
089 * This may involve rounding or truncation.
090 *
091 * @return the numeric value represented by this object after conversion
092 * to type <code>byte</code>.
093 * @since JDK1.1
094 */
095 public byte byteValue() {
096 return (byte) intValue();
097 }
098
099 /**
100 * Returns the value of the specified number as a <code>short</code>.
101 * This may involve rounding or truncation.
102 *
103 * @return the numeric value represented by this object after conversion
104 * to type <code>short</code>.
105 * @since JDK1.1
106 */
107 public short shortValue() {
108 return (short) intValue();
109 }
110
111 /** use serialVersionUID from JDK 1.0.2 for interoperability */
112 private static final long serialVersionUID = -8742448824652078965L;
113 }
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